Books, primarily children's books, often include a means for interacting with a reader to help hold the reader's attention, such as by producing a sound in response to an action by the reader. Such sounds also provide additional sensory stimuli which aids in the reader's comprehension and memory of the book's contents. Accordingly, children's books are often designed to induce children to read, as well as to keep a child's interest throughout the book. For example, children's books come in a variety of shapes, sizes, and styles, and have been designed with, among other things, decorative and colorful covers, bright illustrations, scratch and sniff areas, pop-up figures, and lift-up flaps. Many of these features in the books are designed to make the books more appealing to youthful readers and to teach children new skills, such as dexterity, memory, or imagination and reasoning.
Developing children continuously learn new cognitive and physical skills. Books have been recognized as helping children with letter and word recognition, as well as improving their small motor skills. The more interactive the user is with a book, both on a cognitive level and with being able to physically manipulate portions of the book, the greater opportunity there is for the user to learn on a variety of levels.